


Somnophilin' It

by Vexatious



Category: Undertale (Video Game)
Genre: Alternate Universe - Underfell, Creampie, Ecto-Genitalia (Undertale), Ecto-Penis (Undertale), Ecto-Tongue (Undertale), Ecto-Vagina (Undertale), Explicit Language, Explicit Sexual Content, Fontcest, Kidnapping, M/M, Non-Consensual Bondage, Non-Consensual Somnophilia, Physical Abuse, Rape/Non-con Elements, Sanscest - Freeform, Sexual Abuse, Skeleton Sex (Undertale), Underfell Sans, sancest
Language: English
Status: In-Progress
Published: 2017-12-31
Updated: 2017-12-31
Packaged: 2019-02-25 22:07:12
Rating: Explicit
Warnings: Rape/Non-Con
Chapters: 1
Words: 1,715
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/13222197
Author URL: https://archiveofourown.org/users/Vexatious/pseuds/Vexatious
Summary: Red is looking for a quickie, and decides to try out Boss’s new toy. Too bad Sans is sleeping… not that that’ll stop Red.





	Somnophilin' It

**Author's Note:**

> Inspired by: [18+ artwork](http://muskkamu.tumblr.com/post/167467409824/morning-surprise)  
> Check out my Tumblr: [vex-bittys](http://vex-bittys.tumblr.com)

Red didn’t even bother turning on the light in the small bedroom. He knew this space intimately enough that the moonlight bleeding in through the curtains would suffice. As long as he could make out the vague shape sprawled on the bed, he could execute his plan. Licking his sharp teeth, paying a bit of extra attention to the gold-plated one, he began to rub at his pelvis. The shape in the bed didn’t stir even as a dim red glow spread throughout the room. Red chuckled darkly.  _Perfect_.

Slowly, silently, Red lifted the blanket off of the sleeping monster beneath it- a skeleton like himself. In fact, this skeleton was a version of himself from another universe that Boss had brought back to Underfell a few months ago. Red didn’t need to see the sleeping monster’s face; he had those features memorized from long sessions of scowling in the mirror to get the expression just right. This guy, this  _Sans the skeleton_ , had some slight differences in his facial structure though.

His eyelights shone a pure untainted white, unlike the gleam of crimson that sparkled in every Fell monster’s gaze. His teeth were unsharpened and provided no defense in a fight. Lastly, Sans possessed none of the aged scarring of his doppelganger, though Boss had given him some fresh marks with his violent brand of love-making that should show nicely as scars once they healed.

Lifting up the plain white t-shirt that his not-quite double wore in place of pajamas, Red ran his hands down the smooth unmarred bones of Sans’ ribs, so unlike his own, his touches light so as not to wake the slumbering skeleton. Only a monster who lived in a peaceful universe could sleep so deeply and allow themselves to be so unguarded.

Sans’ state of complete unconsciousness served Red’s purposes just fine as the Underfell skeleton’s hands drifted lower to caress the smooth curves of Sans’ pelvis. A blue glow radiated from Sans’ pubic symphysis and quickly spread throughout his entire body.  _Such a responsive little slut_ , thought Red with a hungry leer.

Red climbed onto the bed slowly and carefully, pausing frequently to check that Sans slept on, undisturbed. With smooth, unhurried movements, Red spread Sans’ legs and settled himself between them. Keeping a wary eyelight on the dimly lit skull resting on the pillow, Red caressed Sans’ tailbone, allowing his fingertips to stray into the foramen of his sacrum. Leaning down, Red basked in the heat radiating from Sans’ pelvis before flicking out his tongue to stroke and curl around the sensitive cartilage of his pubic symphysis. Red smirked, watching as luminous cobalt magic coalesced into a delectably slick entrance. The newly formed pussy lit the room like a soothing LED lamp, throwing Sans’ relaxed features into sharp relief.

The heavily sleeping skeleton hadn’t moved an inch or uttered so much as a dozy snore, but Red could see a flush of bright blue across Sans’ rounded cheekbones.  _Too fucking cute_. Now the delicate work would begin because there was no way Red’s thick, throbbing cock could fit into Sans’ tight little cunt without some preparation, but working too hard or too fast to stretch that tantalizing hole risked awakening the other skeleton. As much as he wanted to plunge his tongue deep inside of Sans and lap up his arousal like a thirsty dog, he had to do things a quieter, gentler way.

Licking one slim phalange, Red slowly inserted it into the waiting orifice.  _Fuck_ , Sans’ pussy was so warm and wet that it squelched loudly as Red casually slid his finger inside to the knuckle. When he tried to pull out again, Sans’ pussy walls clung to him, trying desperately to maintain that satisfying fullness.

“Such a hungry cunt,” Red purred under his breath, setting a leisurely pace as he pumped first one, then eventually two digits in and out of the slick, sucking hole. Once he could sink his phalanges in fully without resistance, Red started to scissor them, spreading Sans’ pulsating hole wide enough to take his cock.

Sans groaned and shifted, and Red froze, fingers still partially buried in Sans’ pussy as he waited for his counterpart to settle. After a long, anxious moment, Red withdrew his fingers, eliciting no reaction whatsoever. Good. Now Red could let the real monster loose. Shoving the waistband of his basketball shorts down, Red let his aching erection spring free, a strand of precum already oozing from the tip to drip onto the bedsheets as if to mark his territory.

Red lubricated his thick crimson cock with the sticky fluids still coating his fingers. Taking one last look at Sans’ impassive, unconscious face, Red proceeded to rub the head of his needy shaft against Sans’ arousal-soaked slit.  With a muffled groan, he infiltrated the silky depths of Sans’ cunt with just the head of his cock, pausing frequently as he drove in inch after inch of his length until he hilted in the other skeleton’s sultry, clenching insides. Red could see his bright red shaft twitching through the sheen of Sans’ translucent blue magic, and he liked the view. _I could get used to this_ , he thought as he began to thrust shallowly.

If Red wanted Sans to stay asleep- and he did- then a rough, forceful pounding was out of the question. Red couldn’t just batter away at Sans’ pussy and expect him not to notice, but the subdued pace had its own drawbacks. The smooth, deliberate movement of Red’s hips was equal parts titillating and maddening. Lust scorched his bones and magic as he consumed every iota of pleasure dragged from Sans’ limp, pliant body. The thrumming sapphire magic provided the perfect living cocksleeve for Red’s sexual perversions.   

The friction of Sans’ narrow little cunt walls felt exhilarating, but Red craved more. He braced his hands on the crests of Sans’ hips and bucked into him more powerfully. Sans mewled softly in his sleep, spurring Red on. His emboldened efforts evoked a carnal need for release in the Fell skeleton. Growling, Red gradually increased his pace, stroking his cock on Sans’ slick insides, but satisfaction danced just out of his reach. Sans’ entire body shuddered when Red adjusted the angle of penetration to reach deeper with his shaft into Sans’ fluttering hole. Red paused again, thwarted by the sensitivity in Sans’ sweet pussy that threatened to wake him.

Once more, Sans settled, and once more, Red resumed fucking him. The erotic melody of slippery magic colliding and sliding together played across Red’s ear canals. Fuck, he wanted to completely destroy Sans’ pussy, just pound that hot little hole until Sans’ juices splashed out with each violent thrust. Red didn’t know how much longer he could maintain his composure. The pleasure rippling through his body was too intense.

Grabbing Sans’ right leg, Red twisted the other skeleton’s entire body, not even bothering with caution.  With their bodies in the new position, pressure rapidly began to build along the underside of Red’s cock. Sans whimpered again, louder and more coherently this time, and Red forced himself to roll his hips in a slow, steady rhythm, fighting the urge to slam into Sans fast and hard the way his throbbing magic begged him to.

The overwhelming urge to cum, to fill Sans’ arousal-dripping cunt with his thick hot seed drove him on, but the longer he fucked Sans at the excruciatingly slow pace, the more frustration welled up within him. He was just fucking edging himself. He’d never reach that blissful, long-awaited release at this rate! He didn’t care about waking Sans up anymore; Red just wanted to cum!

Sweat beaded on Red’s forehead as he hammered at Sans’ pussy, rocking the other skeleton’s body and rattling the headboard of the bed. Red tugged Sans’ whole pelvis into his lap, tightening his grip and pulling all the way out before impaling Sans again on his thick, engorged length. Each thrust left Red bottomed out in the trembling blue magic. Red’s ragged panting couldn’t mask the sounds of Sans awakening though. Red just didn’t care anymore, his entire focus on achieving his own orgasm.

“N-ngh… ah… AAHHH!” Sans screamed himself into consciousness to the sensation of having his delicate cunt stuffed to the breaking point with an unrelenting cock.

“good morning, sweetheart,” Red huffed, not missing a beat. Saliva dripped from his protruding tongue onto Sans’ sensitive pelvis, and he shuddered at the overwhelming stimulation.

“wh-wha… r-red?” The sinister skeleton’s shaft raked Sans’ tender walls repeatedly, and Sans barely had time to process the scene before his back arched, his pussy clenched, and he came hard, fluids gushing from his battered hole as Red continued to fuck him.

“don’t worry about it, sans. I’m… almost… done…” Red jerked his hips forward a final time, crying out in mindless bliss as his hot load poured into Sans’ magic, filling it to the brim and overflowing onto the already stained sheets. Sans’ cry of pleasure mimicked Red’s as his cunt spasmed, accepting every last drop of cum that the sharp-toothed skeleton had to offer.

Red hopped off of the bed, yanking his basketball shorts back up to their proper place. As he turned to leave, Sans called out to him. Red glanced back over his shoulder. Sans’ femurs were discolored and sticky with their combined magic, and his summoned pussy was swollen with with Red’s vibrant cum.

“red please… please unchain me…” Sans shook his leg, jostling the shackle and chain attached to his ankle, which was raw and oozing marrow from many attempted escapes. The metal jangled enticingly, but Red knew better than to touch the locking mechanism. The whole thing glowed with the blood-red magic Boss had placed there. Only Red’s fearsome younger brother could remove it.

Red barked out a laugh. “you’re a pretty good fuck, but not worth getting dusted over.”

“red… red… please! you know what he’s like!”

“oh, believe me, i know. before he found you, i was the one chained to that bed.” Red turned away again.

“wait… no!”

Red vanished into the hallway, but he peeked back around the doorframe to offer a final comment to his helplessly trapped double.

“better you than me, buddy, chum, friendo. see ya tomorrow night…”


End file.
